On his first day on the job in Washington, Interior Secretary Ryan Zinke rode to his new office on a National Park Service horse. Next week, he heads to Utah for another horse-powered photo op through the tougher terrain of the Bears Ears, which President Obama designated a national monument. “I'm going to ride a horse, like Teddy Roosevelt, and see the land and talk to the Navajo and the nations of tribes,” Zinke said.

The trip is part of Zinke’s review of large-area national monument designations made under presidents Bill Clinton, George W. Bush, and Barack Obama (although Bush established just four of the 24 monuments.). Theodore Roosevelt would likely be outraged by the underlying mission—scaling back the monuments—that Zinke has been tapped to carry out as he trots along on whatever trusty steed his Utah hosts rustle up for him.

Zinke’s boss, President Donald Trump, recently signed an executive order that calls for the “review” of national monument designations under the Antiquities Act of 1906—the one that Roosevelt, the country’s first conservationist-president, signed 100 years ago that gave him the authority to create nearly 20 national monuments.

Decrying “federal overreach,” Utah Republican Congressmen Jason Chaffetz and Rob Bishop are plainly determined to reverse a number of the previous presidents’ monumental designations, including the 1.7 million acre Grand Staircase-Escalante National Monument, Bears Ears, and other “worst of the worst” “land grabs,” as Bishop put it.

Trump’s executive order, his latest attempt to turn back the hands of Obama-time, is also an affront to Roosevelt’s conservation handiwork. In the words of the order, Trump aims to review those designations that could interfere with “energy independence, restrict public access to and use of federal lands, burden state, tribal, and local governments, and otherwise curtail economic growth,” especially when those designations suffered from “lack of public outreach and proper coordination” with state, local, and tribal officials. His moves will breathe new life into controversies that pit interests in energy, lumber, and fisheries against environmentalists, scientists, the tribes, and Americans on vacation.

In Utah, Indian tribes hailed the Obama’s Bears Ears move as one that would honor their ancestral lands and religious practices. Bears Ears is the first monument to be established as a direct result of tribal pressure and only national monument in the country that the federal government and the Bears Ears Inter-Tribal Coalition—a partnership of the Hopi, Navajo, Ute Indian Tribe, Ute Mountain Ute, and Zuni—manage together. Palentologists were heartened that the Bears Ears designation added protections to fossil-rich lands. Yet Obama held off including the adjacent Red Canyon area that holds an even larger trove of fossils. That region is one of the largest uranium mining sites in the country, and mining interests successfully argued that yellow cake deposits would be imperiled by closing off Red Canyon to extraction activities.

But such “federal overreach” may help business more than it hurts it. Tourism is booming in Utah town of Escalante, population 895. Dennis Waggoner, the president of the Escalante-Boulder Chamber of Commerce, extolled the virtues of the monument in a Salt Lake Tribune op-ed, writing, “Business has never been better. My business, Escalante Outfitters, is employing more people with a higher payroll than ever before: Our sales are at record levels, and we are expanding by building new facilities to accommodate this demand.” He also refuted criticism about the monument’s negative effects on the local timber and coal industries.

Almost a continent away a similar battle of wills is playing out in New England. Maine has had a long running and acrimonious debate over the Katahdin Woods and Waters National Monument, in the northern part of the state. Roxanne Quimby, one of the cofounders of Burt’s Bees skin-care products, purchased nearly 100,000 acres of woods, angering local residents by restricting hunting and other activities. Quimby had tried to persuade the federal government to turn her lands into a national park. Thwarted by opposition from Senator Susan Collins and Representative Bruce Poliquin, among others, Quimby set her sights on a next-best alternative: A national monument (which requires a presidential proclamation rather than an act of Congress). Obama signed that proclamation before he left office.

Many Mainers in the Katahdin region have moved to embrace expanded eco-tourism and other economic development opportunities that the monument offers. Detractors continue to argue that seasonal, low-paying tourism jobs fall short of the state’s needs (and restrictions on hunting that have come with the designation don’t win many fans in Maine). But like his Utah counterpart, Maine businessman Matthew Polstein is convinced that boom times have arrived. Thanks to tourists flocking to the monument, his restaurant business has grown more than 33 percent year over year and his snowmobiling business, 61 percent.

Meanwhile, with Zinke trotting around and his pal Trump safely ensconced in the White House, Maine’s perennially cantankerous Governor Paul LePage, a long-time opponent of the monument, has moved in for the kill. This week, he came before before the House Natural Resources Subcommittee on Federal Lands with a plea to revoke the designation. His faltering testimony, however, may not have convinced many lawmakers. Asked about the size of the state’s tourism industry and the economic impact of Acadia National Park, LePage could not recall specific facts or figures. To make matters worse, as Bangor Daily News blogger David Farmer noted, LePage un-gubernatorially disparaged the Katahdin region as a “mosquito-infested wasteland that no one would want to visit”), and proclaimed that the paper mills are coming back—even though they never will.

These intense conservation debates will keep courts busy for the foreseeable future. Indeed, the fate of the Northeast Canyons and Seamounts Marine National Monument, the East Coast’s first marine monument, has already landed in federal court. The monumental designation infuriated an East Coast fishing industry already undone by climate change and government restrictions on catches. A coalition of fishing groups have filed a lawsuit against the monument and recruited the Pacific Legal Foundation, a conservative/libertarian public interest legal group, to press their case. Their argument rests on the premise that the Antiquities Act only applies to areas on land.

But the real push behind the war on the monuments is coming from the Oval Office. When it comes the undoing accomplishments of his predecessors, few presidents have been exhibited the raw vindictiveness of Donald Trump. Protecting the rights of minorities, preserving the environment, encouraging conservation and supporting new industries to replace dying ones have never been high on the president’s agenda. Critics continue to disagree over the specifics of the constraints on presidents on national monument questions. But the fact that no president has ever made such a move is just the kind of perverse incentive that Trump needs to strip away national monument designations from sea to shining sea. In Trump’s world, photo ops of his horseback-riding Interior Secretary serve his primary mission of obliterating Barack Obama’s legacy. Teddy Roosevelt is just collateral damage.